Ghost Cake

Make cake: Preheat oven to 350°. Line two 8” cake pans with parchment and grease with cooking spray. In a large bowl, whisk together flour, cocoa powder, baking soda, and salt.  In another large bowl, whisk hot coffee and sugar together. Add oil and sour cream and whisk to combine. Pour into dry ingredients and whisk until just combined.  Divide batter between prepared pans and bake until a toothpick inserted in middle comes out clean, 25 to 30 minutes. Let cool 15 minutes, then invert onto a wire cooling rack and let cool completely.  Make meringues: Preheat oven to 225°. Line a large baking sheet with parchment paper. In a small bowl combine sugars. In a large bowl using a hand mixer (or in the bowl of a stand mixer fitted using the whisk attachment) beat egg whites and cream of tartar on low speed until whites are broken up and cream of tartar is mostly mixed in. Increase speed to medium and continue beating. When egg whites are frothy, slowly pour in sugars a little at a time. Increase speed to high and continue beating until medium peaks. Slowly add vanilla and keep beating until egg whites are stiff peaks. Transfer egg whites to a piping bag with a large round tip.  Pipe ghosts onto prepared baking sheet by piping a large circle, lifting slightly and piping a slightly smaller circle, then lifting slightly again and piping another slightly smaller circle. Bake meringues until outsides are hard, 1 hour and 20 minutes. Let cool completely.  Make buttercream: Wrap cooled cake layers in plastic wrap and freeze for 20 minutes. In a large bowl using a hand mixer (or in the bowl of a stand mixer with the paddle attachment), beat butter until smooth. Add powdered sugar and a pinch of salt and beat until no lumps remain. Add heavy cream and vanilla and beat until combined. Add more heavy cream, 1 tablespoon at a time, if needed until desired consistency is reached. Frosting should hold its shape, but be easily spreadable. Scoop out about ¼ cup of frosting and reserve for later.  Unwrap cake layers and using a serrated knife, level tops of cakes if needed. Place one layer on a serving platter and spread about half of the frosting on top with an offset spatula. Place second layer on top and frost tops and sides with remaining frosting. Use a bench scraper to smooth sides and top.  Dye the reserved buttercream black and place into a pastry bag with a small round tip. Pipe eyes and mouths onto cooled ghost meringues.  Make ganache: Place chocolate chips into a heat safe bowl. In a small pot over medium heat, heat heavy cream until bubbles form around the edges of pan. Pour hot heavy cream over chocolate chips and let sit 1 minute. Whisk ganache until smooth and completely combined.  Pour about half of the ganache onto the top of the cake and use an offset spatula to smooth ganache. Gently push ganache to the edges of the cake and help guide the chocolate to drip down the side. Add more ganache as needed. Arrange ghost meringues on top of cake.